U.S. patent number 5,846,079 [Application Number 08/810,305] was granted by the patent office on 1998-12-08 for single tooth dental restoration system.
This patent grant is currently assigned to Implant Innovations, Inc.. Invention is credited to Helmut Knode.
United States Patent |
5,846,079 |
Knode |
December 8, 1998 |
Single tooth dental restoration system
Abstract
A system for making anatomically correct and aesthetically
pleasing dental restorations, including a modeling structure for
fashioning a custom-made impression coping and a method of using
the model to form said impression coping. A healing abutment used
in second stage surgery to form an opening in the gingiva of a
dental patient is attached to an implant analog within the model.
Impression material is poured into the modeling receptacle around
the healing abutment so as to form a model of the patient's
gingival layer, including a cavity in the model corresponding to
the opening in the patient's gingival layer. A narrow coping shaft
is attached to the implant analog within the modeling receptacle,
and a modeling material is poured into the cavity and allowed to
harden around the narrow coping shaft, thus forming an impression
coping with a transmucosal section replicating the size and shape
of the healing abutment. The impression coping may thereafter be
connected to a dental implant in the patient's jawbone (after
removal of the healing abutment) so that an impression may be taken
in the usual manner to be used in making a stone model of the
surgery site, which in turn may be used in fashioning an artificial
tooth.
Inventors: |
Knode; Helmut (Trier,
DE) |
Assignee: |
Implant Innovations, Inc. (Palm
Beach Gardens, FL)
|
Family
ID: |
21755578 |
Appl.
No.: |
08/810,305 |
Filed: |
February 28, 1997 |
Current U.S.
Class: |
433/213;
433/214 |
Current CPC
Class: |
A61C
8/008 (20130101); A61C 8/00 (20130101); A61C
8/0001 (20130101) |
Current International
Class: |
A61C
8/00 (20060101); A61C 011/00 () |
Field of
Search: |
;433/172,173,174,175,176,214,213 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0 442 855 A1 |
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Aug 1991 |
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EP |
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0 657 146 A1 |
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Jun 1995 |
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EP |
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1 291 470 |
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Oct 1972 |
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GB |
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Other References
Richard J. Lazarra, "Managing the Soft Tissue Margin: The Key to
Implant Aesthetics", PP & A, Jun./Jul. 1993, vol. 5 No. 5, pp.
81-87. .
Exhibit A, a drawing of a healing abutment. .
Exhibit B, an assembly drawing of a coping and the component
drawings which comprise the coping assembly. .
Lewis, S.G. et al., Single Tooth Implant Supported Restorations,
Intl. Jrnl. of Oral & Maxillofacial Implants, vol. 3, No. 1,
pp. 25-30, 1988. .
Lewis, S. G. et al., The "UCLA" Abutment, Intl. Jrnl. of Oral &
Maxillofacial Implants, vol. 3, No. 3, pp. 183-189, 1988. .
Perri, George et al., Single Tooth Implants, CDA Journal, vol. 17,
No. 3, pp. 30-33, Mar. 1989. .
DIA.TM. Dental Imaging Associates, Inc., IMPLA-MED The Source, The
Anatomic Abutment System.TM., front and back covers, pp. 1-10,
Copyright Oct. 1991. .
Steri-Oss.RTM., The Future of Implant Dentistry Product Catalog,
Feb. 1992, cover and back pages, pp. 7, 14. .
Branemark System.RTM. SMILINE, Product Catalog Prosthetics,
(Nobelpharma) 1991, 24 pages. .
Steri-Oss.RTM. A Denar Affiliate, The Future of Implant Dentistry,
Product Catalog, Sep. 1990, 36 pages. .
IMTEC Hexed-Head.TM. Implant System, Spring 1993 Catalog, IMTEC
Corporation.RTM., 15 pages. .
Interpore International, "IMZ.TM. Prosthetic Flow Chart", Jul.
1993, 2 sheets. .
Impla-Med.TM. Incorporated, The Source, "Come to the Source. The
Choice is Clear." Catalog, Mar. 1991, 16 pages. .
Stryker.RTM. Dental Implants, "Surgical Flexibility Prosthetic
Simplicity" Stryker Universal Hextop Component.TM., Catalog Data
Sheet, undated, 8 sheets. .
Stryker.RTM. Dental Implants, Price List, Jun. 1, 1993, 46 pages.
.
Oratronics, Inc., "Options for Oral Implantology . . . Oratronics
Endosseous Tri-Dimensional T-3D Oral Implant Healing System
(OIHS)", 1978, 8 pages..
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Primary Examiner: O'Connor; Cary E.
Attorney, Agent or Firm: Arnold, White & Durkee
Claims
What is claimed is:
1. A modeling structure for use in a single-tooth dental
restoration system, said modeling structure comprising
a receptacle for receiving a flowable dental impression material,
said receptacle including a base portion and a sidewall portion,
said base portion having an opening therein defining a socket for
receiving a dental implant structure, and
means substantially replicating the gingival aspect of a dental
implant disposed substantially within said socket, a proximal end
of said replicating means being accessible through said opening in
the base portion of said receptacle, said proximal end being
adapted to receive a dental restorative component thereon.
2. The modeling structure of claim 1 wherein the dental implant
structure comprises an implant analog.
3. The modeling structure of claim 1 wherein said socket opens into
the bottom of said receptacle.
4. A modeling structure for use in a single-tooth dental
restoration system comprising:
a receptacle for receiving a flowable dental impression material,
said receptacle including a base portion and a sidewall portion,
said base portion having an opening therein defining a socket;
a dental implant structure disposed substantially within said
socket, a proximal end of said dental implant structure being
accessible through said opening in the base portion of said
receptacle, said proximal end adapted to receive a dental
restorative component thereon.
5. The modeling structure of claim 4 wherein a healing abutment is
connected to the proximal end of said dental implant structure,
said healing abutment being positioned above said base portion and
within said sidewall portion of said receptacle.
6. The modeling structure of claim 5 wherein said healing abutment
substantially corresponds in size and shape to the trans-tissue
portion of a natural tooth.
7. The modeling structure of claim 6 wherein a body of dental
impression material is set up within said receptacle, said
impression material surrounding the sides of said healing abutment
and in contact with said sidewall portion.
8. The modeling structure of claim 4 wherein a body of impression
material is set up within said receptacle, said impression material
forming a model of gingivaadjacentto an implant site, said model
including a cavity above said dental implant structure
corresponding in size and shape to the trans-tissue portion of a
natural tooth.
9. The modeling structure of claim 8 wherein an impression coping
is connected to the proximal end of said dental implant structure,
said impression coping including a trans-tissue portion formed
within said cavity and corresponding in size and shape to the
trans-tissue portion of a natural tooth.
10. The combination of claim 9 wherein said impression coping is a
pick-up coping.
11. A set of dental components for use with a dental root means
fixed in a site with an overlying gingiva layer having an opening
to the root means, said set comprising:
a healing member for forming said opening in said gingiva;
means to attach said healing member to said root means;
an impression coping having a trans-tissue portion of the same size
and shape as said healing member so as to fit fully into said
opening in place of said healing member, part of said trans-tissue
portion being made of modeling material; and
means to attach said impression coping to said root means with said
trans-tissue portion fitted into said opening.
12. The set of dental components according to claim 11 wherein said
impression coping is a pick-up coping.
13. The set of dental components according to claim 11 wherein said
healing member has a unique size and shape corresponding to the
trans-tissue portion of a natural tooth.
14. An impression coping for use in fabricating a model of a
patient's edentulous jawbone site containing root means with an
overlying gingiva layer having an opening to the root means formed
from a healing member, said impression coping comprising:
a transmucosal portion having a size and contour replicating that
of said healing member, part of said transmucosal portion being
made of modeling material, said transmucosal portion being adapted
to fit within said opening formed from said healing member;
an impression portion adjacent to the transmucosal portion for
extending into impression material; and
means for fastening said impression coping to the root means.
15. The impression coping of claim 14 wherein said impression
coping is a transfer coping.
16. The impression coping of claim 14 wherein said impression
coping is a pick-up coping.
17. The impression coping of claim 14 wherein said healing member
has a unique size and shape corresponding to the trans-tissue
portion of a natural tooth.
18. The impression coping of claim 14 wherein said impression
coping has an elongated body with a through bore for passage of
fastening means to attach the impression coping to the root
means.
19. A method of fabricating a model of a patient's edentulous
jawbone site containing root means with an overlying gingiva layer
having an opening to the root means, said method comprising the
steps of:
attaching a healing abutment to a gingival end of said root means,
said healing abutment corresponding in size and shape to the
trans-tissue portion of a natural tooth, said opening in said
gingival layer thereafter conforming to the size and shape of said
healing abutment;
placing a root means analog into a socket formed in the bottom of a
modeling receptacle, a body portion of said root means analog being
disposed substantially within said socket, a proximal end of said
root means analog being accessible through an opening into said
socket at a base portion of said modeling receptacle;
attaching said healing abutment to said proximal end of said root
means analog such that said healing abutment is positioned above
said base portion and within a sidewall portion of said modeling
receptacle;
pouring an impression material into said modeling receptacle to a
desired depth surrounding said healing abutment so as to form a
model of said gingiva layer;
removing said healing abutment from said model of said gingiva
layer to define a cavity in said model corresponding in size and
shape to said healing abutment;
attaching an impression coping to the proximal end of said root
means analog, said impression coping including a narrow impression
portion extending through said cavity and having a width
substantially smaller than said cavity;
pouring a modeling material into said cavity and allowing it to
harden around said impression coping so as to form a modified
impression coping having a transmucosal portion replicating the
size and shape of said healing abutment;
removing said modified impression coping from said model and
attaching said impression coping to said root means;
taking a dental impression of said patient's jawbone site with said
modified impression coping in place; and
using said dental impression to make a stone model of the patient's
jawbone site.
20. A method of fabricating an impression coping for use in dental
restorative surgery from a healing abutment adapted to form an
opening in a patient's gingival layer corresponding in size and
shape to the trans-tissue portion of a natural tooth, said method
comprising the steps of:
attaching said healing abutment to an artificial root means
disposed within a modeling receptacle such that said healing
abutment is positioned above a base portion and within a sidewall
portion of said modeling receptacle;
pouring an impression material into said modeling receptacle to a
desired depth surrounding said healing abutment so as to form a
model of said patient's gingival layer;
removing said healing abutment from said model to define a cavity
in said model corresponding in size and shape to said healing
abutment;
attaching a narrow coping shaft to said artificial root means
within said modeling receptacle, one end of said narrow coping
shaft including an interlocking member adapted to connect to either
of said root means and said artificial root means, said narrow
coping shaft extending through said cavity and having a width
smaller than said cavity; and
pouring a modeling material into said cavity and allowing it to
harden around said narrow coping shaft so as to form a transmucosal
section replicating the size and shape of said healing abutment,
said impression coping being defined by the combination of said
narrow coping shaft and said transmucosal section.
21. A method of fabricating an impression coping for use in dental
restorative surgery, said method comprising the steps of:
attaching a narrow coping shaft to an artificial root means
disposed within a modeling receptacle, said narrow coping shaft
extending through a cavity formed in said modeling receptacle
replicating a gingival aperture formed at an implant site; and
pouring a modeling material into said cavity and allowing it to
harden around said narrow coping shaft so as to form a transmucosal
section replicating that of a natural tooth, said impression coping
being defined by the combination of said narrow coping shaft and
said transmucosal section.
Description
CROSS REFERENCES TO RELATED APPLICATIONS
This application claims the benefit of priority of provisional U.S.
patent application Ser. No. 60/012,567, filed on Feb. 29, 1996.
FIELD OF THE INVENTION
The present invention relates generally to dental restoration
systems in which an artificial tooth is fashioned to replace a lost
natural tooth and attached to a dental implant structure at the
site of the missing tooth. More particularly, the present invention
is directed to a set of components and a method of using same to
fashion an artificial tooth closely replicating the appearance of a
lost natural tooth.
BACKGROUND OF THE INVENTION
Dental implants are becoming an increasingly popular means for
restoring lost teeth in wholly or partially edentulous patients. A
dental implant typically comprises a threaded titanium cylinder
having a length ranging between about 5 mm and 13 mm and a diameter
ranging between about 3 mm and 6 mm. The most common type of dental
implant now in use has a hexagonal post or boss (commonly called a
hex) on its gingival end. The hex of the implant is adapted to
anti-rotationally mate with a corresponding hexagonal socket on an
artificial tooth or abutment to which the restored tooth is
attached.
The restoration of a single tooth typically occurs in two stages.
In the first stage, a dental implant in inserted in the jawbone of
a dental patient in the location of the natural root of the lost
tooth. After the first stage surgery, the implant is left in
position in the jawbone, covered by the patient's fleshy gum
tissue, for several months until it becomes osseointegrated within
the patient's jawbone. Thereafter, in the second stage, the gum
tissue is opened to expose an end of the implant, and a healing
abutment is attached to the implant until the surrounding gum
tissue heals around the abutment. After the gum tissue has healed,
the healing abutment is typically removed and the implant is
available to support an artificial tooth. The process of fashioning
the artificial tooth usually begins with the step of attaching an
impression coping to the implant and making a dental impression of
the coping and surrounding teeth. The impression is then removed
from the patient's mouth so that it may be used to make a stone
model of the patient's case.
In one technique using a "pick-up" type impression coping, the
coping is automatically "picked up" (i.e. removed from the implant)
during removal of the impression material. In another technique
using a "transfer" type impression coping, the coping remains
attached to the implant during removal of the impression material,
but is then removed from the implant by the clinician and
"transferred" back into the impression material. In either case,
the coping is designed to be positioned within the impression
material in the same orientation as it had been positioned in the
implant. An implant analog is then attached to the coping and a
stone model is made. Thereafter, the artificial tooth is fashioned
on the implant analog within the stone model and ultimately removed
from the stone model so that it may be attached to the actual
implant within the patient's mouth.
One of the most important aspects of a successful restoration is
that the restored tooth must closely replicate the appearance of
the lost natural tooth with respect to its "emergence profile"
(i.e., the portion of the tooth which extends through and emerges
from the gums). The aesthetic aspect of the dental restoration is
particularly important when a single anterior (i.e. front) tooth is
being restored. Nevertheless, an aesthetically pleasing or
anatomically correct emergence profile is difficult to achieve with
dental restorative components known in the art. Part of the reason
for this is that components such as healing abutments and
impression copings are typically not dimensioned to perfectly
replicate the dimensions of a natural tooth where it emerges from
the gum. For example, natural teeth generally have a non-round
shape where they emerge from the gum comprising a shorter dimension
and a longer (mesial-distal) dimension. In contrast, many of the
healing abutments known in the art have a circular cross section,
typically with a diameter of about 4.5 mm to 8.0 mm to approximate
the mesial-distal dimension of the tooth being replaced. At the
same time, many of the impression copings of the prior art are all
one size, about 4.5 mm in diameter. As a result, a gap is left in
the gingiva, around the impression coping, and impression material
fills this gap when an impression is taken. The gingiva also tend
to collapse into this gap, resulting in less than accurate
replication of the conditions in the patient's mouth. As a further
consequence of these problems, it is difficult to make soft issue
models accurately. Stone models replicate these errors, and this
requires technicians to shape the stone manually to comply with the
conditions in the patient's mouth, or risk producing a crown with
an inaccurate emergence profile or crown to abutment margin that is
misplaced.
In view of the above-described problems, there is a need for a
dental restoration system using components which closely replicate
the dimensions of natural teeth, to facilitate the fashioning of
artificial teeth having emergence profiles closely replicating
those of lost natural teeth. The present invention is directed to
addressing this need by providing new surgical and laboratory
components, and new procedures, to further improve the art of
making anatomically correct and aesthetically pleasing dental
restorations.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, there is
provided a modeling structure for use in fashioning an impression
coping to be used in a single-tooth dental restoration system. The
modeling structure comprises a receptacle including a base portion
and a sidewall portion within which a flowable dental impression
material may be poured. A socket formed within the base portion of
the receptacle is adapted to receive an implant or implant analog
therein, such that a proximal end of the implant or implant analog
is accessible through an opening in the base portion of the
receptacle. The proximal end is adapted to receive a dental
restorative component thereon, such as a healing abutment or
impression coping.
In accordance with another aspect of the present invention, there
is provided a method of using the modeling structure described
above to form an impression coping from a healing abutment. The
healing abutment corresponds in size and shape to the trans-tissue
portion of a natural tooth and is used to form an opening in the
gingiva of a dental patient in second stage surgery. A first step
of the method is to attach the healing abutment to the implant or
implant analog disposed within the modeling receptacle such that
the healing abutment is positioned above the base portion and
within the sidewall portion of the modeling receptacle. Impression
material is then poured into the modeling receptacle to a desired
depth surrounding the healing abutment so as to form a model of the
patient's gingival layer. The healing abutment is then removed from
the model to define a cavity in the model corresponding in size and
shape to the healing abutment. Next, a narrow coping shaft is
attached to the artificial root within the modeling receptacle. One
end of the narrow coping shaft includes an interlocking member
adapted to interconnect with the artificial root. Then, a modeling
material is poured into the cavity and allowed to harden around the
narrow coping shaft, thereby forming a transmucosal section of a
custom-made impression coping which replicates the size and shape
of the healing abutment. The custom-made impression coping may
thereafter be connected to a dental implant in the patient's
jawbone (after removal of the healing abutment) so that an
impression may be taken in the usual manner to be used in making a
stone model of the surgery site, which in turn may be used in
fashioning an artificial tooth.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other advantages of the invention will become
apparent upon reading the following detailed description and upon
reference to the drawings in which:
FIG. 1 is a longitudinal section that shows an implant installed in
a bone with a healing abutment in place;
FIG. 2 is a longitudinal section that shows a transfer coping used
to make an impression;
FIG. 3 is a longitudinal section that shows a pick-up coping used
to make an impression;
FIG. 4a is a side-sectional view of a modeling structure, with
associated healing abutment and through-bolt shown exploded, which
may be used to fashion the pick-up coping of FIG. 3 according to
one embodiment of the present invention;
FIG. 4b is a top view of the healing abutment shown in FIG. 4a;
FIG. 5a is a side-sectional view of the modeling structure of FIG.
4 after impression material has been poured into the modeling
structure around the healing abutment;
FIG. 5b is a top view of the modeling structure, healing abutment
and impression material shown in FIG. 5a;
FIG. 6 is a side-sectional view of the modeling structure of FIGS.
4 and 5 portraying a cavity formed by the removal of the healing
abutment of FIGS. 4 and 5 and a narrow coping shaft disposed within
the cavity;
FIG. 7 is a side-sectional view of the modeling structure, cavity
and narrow coping shaft of FIG. 6 after modeling material has been
poured into the cavity to form a transtissue portion on said narrow
coping shaft; and
FIG. 8 is a cross-sectional view of a soft tissue model upon which
an artificial tooth may be fashioned according to one embodiment of
the present invention.
While the invention is susceptible to various modifications and
alternative forms, specific embodiments have been shown by way of
example in the drawings and will be described in detail herein.
However, it should be understood that the invention is not intended
to be limited to the particular forms disclosed. Rather, the
invention is to cover all modifications, equivalents, and
alternatives falling within the spirit and scope of the invention
as defined by the appended claims.
DESCRIPTION OF SPECIFIC EMBODIMENTS
Turning now to the drawings and referring initially to FIG. 1,
there is shown a dental implant 10 installed in a section of a
patient's jawbone 12 at the site of a missing tooth. The dental
implant 10 serves as an artificial root on which an artificial
tooth will be placed at the completion of the restoration. The
dental implant 10 is typically placed in the jawbone 12 during
"first stage" surgery, after which it is left in position, covered
by the patient's fleshy gum tissue 18, for several months until it
becomes osseointegrated with the jawbone 12. Thereafter, in "second
stage" surgery, the gum tissue 18 is opened to expose an end of the
implant 10, and a healing abutment 14 is attached to the implant
for the purpose of allowing the surrounding gum tissue 18 to heal
in the shape of the abutment. In order to provide for an emergence
profile replicating that of a natural tooth, the healing abutment
14 will preferably closely approximate the size and shape of the
trans-tissue portion of a natural tooth.
U.S. patent application Ser. No. 08/527,508, assigned to the
assignee of the present invention and incorporated herein by
reference, discloses a set of prefabricated healing abutments from
which the healing abutment 14 may be selected, together with
matching impression copings, each being shaped and sized for use in
preparing restorations for particular types of teeth such as, for
example, molars, premolars, bicuspids and incisors. The
prefabricated impression copings in this system are thus designed
to fit perfectly within the gingival aperture formed by an
associated prefabricated healing abutment, so that an impression
made with the coping may thereafter be used to fashion an
artificial tooth having a natural-looking emergence profile. The
present invention provides an alternative system in which
impression copings are "custom-made" to fit perfectly within the
gingival aperture formed by an associated healing abutment.
Preferably, the associated healing abutment will also be
custom-made in order to more closely approximate the emergence
profile of a natural tooth, but it will be appreciated that the
present invention may be utilized with either custom-made or
prefabricated healing abutments.
At any rate, whether custom-made or prefabricated, the healing
abutment 14 shown in FIG. 1 includes a tapered transmucosal section
15 extending from the end of the implant toward an outer surface 16
of the surrounding gingiva 18, beyond which walls 17 of the
abutment extend vertically. A portion of the vertical walls 17 may
be immersed in the gum tissue, below the outer surface 16, together
with the tapered section 15. The implant 10 has an internally
threaded bore 20, surrounded at its gingival opening by a non-round
boss 22, the external cross section of which typically is
hexagonal. The healing abutment 14 has a corresponding non-round
socket 24 enveloping the boss 22. Alternatively, as will be
appreciated by those skilled in the art, the implant 10 and
abutment 14 may be interconnected by means of a non-round socket on
the implant and a corresponding non-round boss on the abutment. In
the illustrated embodiment, a through-bolt 26 passes through an
axial bore 28 in the healing abutment to further secure the
abutment to the implant, as is well known in the art.
FIG. 2 shows a transfer coping 35 of a kind used to take
impressions, buried in an impression material 36. The essential
structure of this impression coping is described and claimed in
U.S. Pat. No. 4,955,811, which is owned by the assignee of the
present invention. This impression coping has a flat surface 37 for
locating it non-rotationally in the impression material. A
hexagonal socket 38 in its base 39 fixes it non-rotationally on the
implant 10. A bolt 41 with an expanded head 42 extends through an
axial bore 40 to attach the impression coping 35 to the implant 10
and hold the coping 35 in the impression material. For the purposes
of the present invention, the impression coping has a tapered
section 44 at its end surrounding the socket 38 that replicates in
size and shape the tapered transmucosal section 15 of the healing
abutment, such as healing abutment 14 shown in FIG. 1. As shown in
FIG. 2, a portion of the base 39 emerges from the impression
material 36, together with the tapered section 44. Preferably, as
described in relation to the healing abutment of FIG. 1, the base
39 will be contoured to mimic the natural cross section of the
tooth being replaced.
FIG. 3 shows a pick-up coping 46 buried in an impression material
36'. This impression coping has a non-round head portion 48 for
anchoring the coping non-rotationally on the implant, if desired,
an axial through bore 40' and a bolt 41' passing through this bore
to attach the impression coping to the implant. The proximal end
42' of the bolt has no expanded head on it for the reason that in
use when an impression is taken, this end of the bolt extends
through a hole in the impression tray (not shown). When the
impression material has set up in the tray, the bolt 41' is
unscrewed from the implant by accessing its proximal end 42' from
the outside, and the tray and the coping 46 remains in (is "picked
up" by) the impression material, being anchored therein by its
expanded head 48. For the purposes of this invention, the pick up
coping 46 functions like the transfer coping 35 of FIG. 2. Thus,
the base 50 and tapered section 52 of the pick-up coping 46 will
preferably replicate the size and shape of the healing abutment
used in second stage surgery.
Now turning to FIG. 4a, there is depicted a modeling structure 54,
with an associated healing abutment 55 and through-bolt 26 shown
exploded, which may be used to fashion a custom-made pick-up coping
or transfer coping according to one embodiment of the present
invention As will be described in detail hereinafter, the
impression coping made from the modeling structure 54 will have a
trans-tissue region which "perfectly" replicates the size and shape
of the healing abutment used in second stage surgery. The modeling
structure 54 consists of a receptacle 56 formed between a base
portion 58 and a sidewall portion 60 which is adapted to receive a
flowable dental impression material. A socket 62 formed within the
bottom of the modeling structure 54 is designed to receiving an
implant analog 64 therein. The implant analog 64 has a non-round
boss 68 and internally threaded bore 20 corresponding to those of
the actual implant 10 (FIG. 1). The implant analog has a proximal
end 66 accessible from above the socket which is available to
support a dental restorative component with a corresponding
non-round socket, such as healing abutment 55. Alternatively,the
implant analog 64 may be equipped with a non-round socket for
attachment to a corresponding non-round boss on a respective dental
restorative component. Moreover, it will be appreciated that the
implant analog 64 may be replaced with an actual implant
duplicating the implant 10 shown in FIG. 1.
FIG. 4b shows a top view of the healing abutment 55. As can be
observed from FIGS. 4a and 4b, the healing abutment 55 has an
asymmetrical shape, designed to approximate the contours of the
trans-tissue portion of a natural tooth. Preferably, the healing
abutment 55 is custom-made to "perfectly" match the emergence
profile of a natural tooth, but it will be appreciated that other
healing abutments may be used, such as the symmetrical healing
abutment 14 shown in FIG. 1 or any suitable healing abutment known
in the art. Similar to the healing abutment 14 of FIG. 1, the
healing abutment 55 shown in FIGS. 4a and 4b includes an axial bore
28' within which a through-bolt 26' passes to secure the abutment
to the implant, as is known in the art, and further includes a
hexagonal socket 24' for non-rotational attachment to the
corresponding hexagonal boss 68 on the implant analog.
Now turning to FIGS. 5a and 5b , there is shown the healing
abutment 55 of FIGS. 4a and 4b attached to the implant analog 64
within the modeling structure 54 after impression material 70 has
been introduced into the modeling structure 54 to a desired
thickness around the healing abutment 14. The impression material
70 flows around and under the healing abutment 55 so as to form an
impression 70 extending from around the healing abutment 55 to the
sidewalls 60 of the modeling structure 54. As shown in FIG. 5a, the
impression 70 thereby comprises a model of the patient's gingiva as
it would appear with the healing abutment 55 attached to the
implant. As shown in FIG. 5b , the sidewalls 60 of the modeling
structure 54 have a circular cross-section, but it will be
appreciated that neither the cross-sectional shape of the sidewalls
60 nor the shape of the healing abutment 55 is material to the
present invention.
After the impression 70 has been formed, the healing abutment 55
may be removed and installed on the actual implant in the patients
jawbone, similar to the healing abutment 14 shown in FIG. 1,
causing the gum tissue (mucosa) overlying the implant to heal in
the reverse-shape of the healing abutment 55 and forming in the
mucosa an aperture surrounding and exposing the gingival end of the
implant. Typically, the healing abutment 55 is affixed to the
implant in the second stage of a two-stage procedure, after the
implant has osseointegrated with the patient's jawbone.
Alternatively, however, the healing abutment 55 may be attached to
the implant immediately after the implant is installed in the
jawbone so that the mucosa heals to the specified shape at the same
time the implant is osseointegrating with the jawbone. The healing
abutment 55 can then be left in the patient's mouth until the soft
(gingival) tissues have matured and the replacement tooth is ready
to be installed on the implant.
As can be seen in FIG. 6, after the healing abutment 55 is removed
from the impression material 70, a cavity 72 identical to the
aperture formed in the mucosa is formed in the impression material
70 surrounding and exposing the gingival end of the implant analog
64. Both the cavity 72 and the aperture in the mucosa will
correspond in size and shape to the healing abutment 55, which
preferably corresponds to the size and shape of the trans-tissue
portion of a natural tooth. An impression coping shaft 74 having a
width narrower than the cavity 72 is attached to the implant analog
64 so that it extends above the implant analog 64 and through the
cavity 72. Preferably, the impression coping shaft 74 is attached
to the implant analog 64 in the same manner as the healing abutment
in FIG. 5a. More specifically, the narrow coping shaft 74 is
indexed non-rotationally with the implant analog 64 by
interconnection of a hexagonal socket on the coping shaft with a
corresponding hexagonal boss on the implant analog, and is
tightened onto the implant analog 64 by means of a screw-post 76
having a threaded end portion 78 engaged within the threaded bore
69 of the implant analog 64. As illustrated in FIG. 6, the narrow
coping shaft 74 comprises a known form of pick-up coping, similar
to that of FIG. 3, but it will be appreciated that the present
invention may also be used to fashion other forms of impression
copings known in the art, including transfer copings similar to
that shown in FIG. 2.
As shown in FIG. 7, an acrylic modeling material 80 is then placed
around the coping shaft 74 in the cavity 72 formed in the
impression material 70, where it hardens on the coping shaft 74 to
the same unique shape as the original healing abutment 55. The
coping shaft 74 and modeling material 80 thereby become conjoined
to form a pick-up impression coping, with the modeling material 80
forming a trans-tissue portion of the impression coping which
corresponds in size and shape to the trans-tissue portion of a
natural tooth. The impression coping may thereafter be used to make
an impression of the site of the missing tooth in the usual manner.
The impression material and impression coping may then be used in
the laboratory in the usual manner to make a model in which the
unique shape of the trans-tissue region of the gingiva is
reproduced, on which to make the artificial tooth.
It will be appreciated that the modeling material 80 used to form
the trans-tissue portion of the impression coping is not limited to
acrylics, but may comprise any of several alternative materials
known in the art, so long as the selected material will harden and
conjoin to the coping shaft 74 in the shape of the cavity 72. The
selected material must also be capable of being introduced into the
cavity 72 without deforming or adhering to the impression material
70. If desired, the coping shaft 74 may incorporate a knurled or
irregular outer surface, or any other suitable means known in the
art, to more readily accept and bond with the modeling material
80.
The model may comprise any suitable model known in the art, but
preferably the model is one having a resilient gingiva-replicating
material providing an artificial soft tissue in which the
uniquely-shaped opening of the original impression material is
faithfully duplicated. Such a soft-tissue model is shown in FIG. 8,
designated generally by reference numeral 82. The soft-tissue model
82 includes a stone foundation 84 rigidly holding an implant
replica 86. A soft tissue layer 88, which replicates the human
gingiva 18 (FIG. 1), overlies the stone part. This layer can be
made of any suitable plastics or rubber-like material having
physical properties such as softness and elastically that resemble
the physical properties of human gum tissue. Certain silicone based
rubber and plastics materials are suitable, preference being given
to those that can be fabricated from a soft flowable state. The
advantage of the soft-tissue model 82 is that the laboratory
technician can manipulate the model exactly as the dentist
manipulates the patient's gingiva.
While particular embodiments and applications of the present
invention have been illustrated and described, it is to be
understood that the invention is not limited to the precise
construction and compositions disclosed herein and that various
modifications, changes, and variations will be apparent from the
foregoing descriptions without departing from the spirit and scope
of the invention as defined in the appended claims.
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